Merged

In Lightroom I select a photo and click "Edit in Photoshop CC 2019". After that I create layers in Photoshop and work with them, but I cannot merge layers. Ctrl+Shift+E or Ctrl+Shift+Alt+E does not work, right-click menu is inactive too. Drop-down lists menu "Layer", "Select", "Image" and "Filter" are not active.My OS: Win10 Pro 1809Solved by deleting CC2019 (ver 20.0.1) and installing CC2018 (ver 19.1.7). Photoshop CC2018 is stable.